During use, work machine components, such as gears of a crawler tractor, typically fail and must be replaced or reconditioned after a certain period of time. The replacement or reconditioning of these components increases the maintenance cost of the work machine.
The failure of the aforementioned components is usually due to the scuffing, wear, or pitting of a surface thereof, e.g. the surface of a gear tooth. Often more than one of these three failure modes (i.e. scuffing, wear, or pitting) occur concurrently to significantly decrease the "life" of the work machine component. The rate at which scuffing, wear, or pitting occurs on the surface of the work machine component is dependent on the amount of friction between the surface of the work machine component and a contacting surface of another work machine component. For example, the rate at which meshingly engaged gear teeth scuff, wear, or pit is dependent on the amount of friction between the contact surfaces of the gear teeth. Therefore, it is desirable to decrease the friction between the contacting surfaces of work machine components so as to decrease the rate at which they scuff, wear, or pit.
Heretofore, mechanical polishing has been utilized to decrease friction between the contacting surfaces of work machine components. In particular, the contacting surfaces are polished so as to remove surface irregularities thereby making the surfaces extremely smooth. Making oil lubricated contacting surfaces smooth reduces the friction therebetween. However, even after extensive mechanical polishing, microscopic surface irregularities (i.e. asperities) will still be present on the contacting surfaces of the work machine components. Therefore, even after mechanical polishing, there is a significant amount of friction between the contacting surfaces of work machine components due to the aforementioned microscopic surface irregularities. The local friction caused by these microscopic surface irregularities can cause the premature failure of the work machine components.
To address the above described drawback of mechanical polishing, various chemical additives have been added to lubricating oils so as to form a surface chemical film on the contacting surfaces of the work machine components. These surface chemical films allow "boundary lubrication" to occur between the contacting surfaces of work machine components. The occurrence of boundary lubrication further reduces the friction between contacting surfaces and increase the durability of work machine components as compared to the friction reduction obtained with mechanical polishing alone.
However, a drawback to using these chemical additives in a lubricating oil is the lack of control of the boundary lubrication on the surface of the work machine component. Another drawback to using these chemical additives in a lubricating oil is the that the lubricating oil must be in contact with the work machine component for a significant period of time before a surface chemical film can be disposed on the contacting surfaces. During the time it takes for the surface chemical film to be disposed on the contacting surfaces of the work machine components the work machine should not be utilized to its full capacity. In other words, during this "break in period" (i.e. the period of time it takes for the surface chemical film to be disposed on the contacting surfaces of the work machine components), the work machine should only be operated in a somewhat gingerly manner. For example, during the break in period the engine of the work machine should only be operated under a predetermined RPM (revolutions per minute) limit. While this break in period allows the surface chemical film to be formed on the contacting surfaces of the work machine components, it is inconvenient for the operator of the work machine. In addition, not adhering to the various constraints of the break in period can lead to the premature failure of work machine components.
What is needed therefore is a method and arrangement for reducing friction between metallic components which overcomes one or more of the above-mentioned drawbacks.